Method of blending fibers



Feb. 17, 1970 J. w n' u s 3,495,304 1 METHOD .OF BLENDING FIBERS Filed July 15, 1966 5 Sheets-Sheet 1 v J. R. WHITEHURST 3,495,304

I METHOD OF BLENDING FIBERS Feb. 17, 1970 Filed July 15, 1966 5 Sheets-Sheet 2 ATTORNEYS Feb. 17, 1970 J. R. WHITEHU-RST v 3,495,304- 7 METHOD OF BLENDING FIBERS Filed Ju1y 15, 1966' 5 Sheets-Sheet 3' &

INVENTOR: Joe E. WHITEHURST ATTORNEYS Feb. 17, 1970 ed July 15, 1966 J. R. WHITEHURST METHOD OF BLENDING FIBERS 2O \Zb 5 Sheets-Sheet 4 8 ATTORNEYS Feb. 17, 1970 J. a. W H ITEHUR S T 3,495,304

METHOD OF BLENDING FIBERS Filed July 15, 1966 5 Sheets-Sheet 5 7 HO HO 10 W 5 fi' n2 INVENTQR.

7 Joe- E. WHH'EHUEST BYMMJI QMM ATTORNEYS view taken substantially, along line 10--10 in FIGURE showing a preferred means facilitating adjustably varying .the intermeshing relationship of "material than the others,

FIGURE 4 is a vertical sectional view, mostly in elevation, taken substantially along line 44 in FIGURE 2A and particularly showing means for adjustably varying the intermeshing relationship of the delivery rolls of the corresponding drafting unit; I

FIGURE 5 is an enlarged fragmentary vertical sectional view, mostly in elevation, taken substantially along line 5-5 in FIGURE 4;

' FIGURE 6 is a vertical sectional view taken substantially along lined- 6 in FIGURE 2A;

FIGURES 7 and 8 are somewhat schematic illustra-- tions of draft-gearing arrangements or gear trains such as may be associated for determining the amount of FIGURE 2A;

FIGURE. 9 is an enlarged fragmentary vertical sectional view through the web supporting and guiding table or platform, taken substantially along line 99 in FIG- URE 2A and showing a preferred arrangement of calender rolls associated with each primary drafting unit; and

FIGURE l'is an enlarged fragmentary elevational the fluted calendar rolls and an associated means for applying downward pressure to the corresponding top fluted calender roll.

Generally, the preferred apparatus for carrying out the method of this invention "comprises a plurality or row of individual side-by-side primary drafting units, there preferably being three or more such primary drafting units,

and four of which are shown in FIGURE 1, and in com- .bined FIGURES 2A and 2B, generally designated at I, II, III and IV, respectively. Fibers from the primary units secondary drafting unit V.

the extent that (a) each unit may draft a that of the other primary drafting units, although the bottom front or delivery rolls of all the primary drafting units and the bottom back or feed roll of the secondary drafting unit may be .directlyinterconnected or driven by a common drive means in theinstant embodiment of the invention, as will be later described. By directly interconnecting all the primary drafting units, uniform output speed of fibers from the primary units is obtained with respect to each other even though periods of acceleration and deceleration vof the drafting units may occur when starting and stopping the same.

As shown, the textile material entering each primary drafting unit I-IV is in the form of a plurality of slivers S, such as'card slivers, drawn from a suitable creel including supply cans C. Primary drafting units I-IV deliver the textile material, in the form of respectivethin, veillike, broad, flat, fibrous primary webs W1, W2, W3, W4,

onto respective curled guide plates 20 which curve downwardly and beneath themselves to invert the respective webs and change their direction of movement by about 90 degrees as they are deposited upon a table or platform 21 and successively formed into stacked or superposed relationship, resulting in a common multilayered or composite webWS.

' Eachweb W1-W4 is drawn or pulled from the respective primary drafting unit over the respective guide plate 20 and along table 21 by a respective calendering device 24 which is constructed to maintain the desired tension draft in the webs while compacting successively superposed webs to assist in homogenous blending of the fibers thereof. Composite web W is thus formed of the stacked with each of the drafting units in FIGURES 2A and 2B draft imparted to corresponding fibers by each corresponding drafting unit,

each primary drafting unit may be self-.

4 superposed webs W1-W4 and passes through secondary drafting unit V which is operatively connected to primary drafting units I-IV to blend and draft the composite web and deliver the same in the form of a web which may be taken upon a suitable roll, not shown, or which may be condensed into a blended sliver S and'coiled into a can 25 for further processing.

Each drafting unit I-V may comprise a plurality of sets of top and bottom drafting rolls, there being four sets of top and bottom drafting rolls providedfor each drafting unit, in this instance. The top and bottom drafting rolls of each drafting unit are indicated at 31-34 and 31'-34', respectively. Althoughthe bottom drafting rolls of drafting units II-V are not shown, the drafting rolls of all the drafting units the manner of drafting unit -I in FIGURE 6. As shown in FIGURE 6, all the drafting rolls preferably are fluted longitudinally thereof and the maximum depth of intermeshing relationship of each set of top-and bottom drafting rolls preferably is limited by means to be later described. However, although it is necessary that the top and bottom front or delivery rolls 34, 34' of each primary drafting =unit I-IV are fluted in the particular disclosed embodiment of the invention and, that, all the bottom" delivery rolls of the primary drafting units are of the top drafting rolls 31-33 and/or the remaining bottom drafting rolls 31-33' different types of fibers to slip I delivery speeds per unit length and distribution of fibers are to be achieved the top. of each primary draftabout the same diameter,

. and means are provided for changing or controlling the maximum depth of intermeshing relationship of the. fluted delivery rolls of the primary drafting units so-that the speed of all the primary webs W1-W4 may be substantially uniform with all the bottom delivery rolls 34" rotat' ing at a common speed, while to the respective drafting rolls. different types of fibers to slip have shown that, in a. typical drafting unit utilizing of fluted delivery rolls, such as rolls 34, 34' 6, rotating at a given speed and interrneshing depth, he delivery drafted different types of fibers varied from about f.p.m. (feet per minute) to about 110 f.p.1 n. For example, a web formed only of Acrilan fibers (acrylic staple) issued from delivery rolls at about 100 f.p.-m., a web fonned only from delivery rolls at about 104 f.p.m'., only of cotton fibers issued from deliv 110 f.p.-m. A blend of about 50 percent cotton fibers and about 50 percent synthetic fibers issued from corresponding delivery rolls at about 105 f.p.m. Further variation in delivery speed of the webs has also been experienced in changing from one denier and/or staple length to another. It is axiomatic that such. variations in cannot be tolerated if the required weight a set positioned at a given and a web formed in the composite web W5 and the resultant drafted material made therefrom. Conversely, if it is assumed that the fibers being drafted through each primary drafting unit I-IV are of a different type than the fibers being drafted through the other drafting units, it may be necessary to deliver the webs Wl-W4 from the respective units at slightly different speeds to allow for differences in stretchability of the different suflicient tension draft therein tudinal movement between the successively superposed.

Since all the drafting rolls 31-34, 31'-34' of each to prevent relative longiprimary webs as'they are may be arranged substantially in of the primary drafting. units I-IV with all the bottom delivery rolls 34' allowing for tendencies of 5 different amounts relative] As to the tendency for different amounts, tests of FIGURE 3 speed of separately of Dacron fibers (polyester staple) issued ry rolls at about Webs while providing for' drafting unit preferably are in the form of fluted rolls, each set of top and bottom drafting rolls preferably is provided with means limiting the extent of intermeshing relationship thereof. Accordingly, each end of each bottorn drafting roll may be journaled in a bearing 36 (FIG- URES 4 and 5), which is preferably an anti-friction hearing and fits in a substantially U-shaped bearing block 37. Each bearing 36 is provided with an enlarged portion 40 thereon whose diameter may be approximately the same as the pitch diameter of the corresponding fluted bottom roll. Also, each end of each top drafting roll may be journaled in a bearing 41, which is preferably an antifriction bearing, and whose reduced end portion fits loosely in the corresponding block 37, and wherein each bearing 41 has an enlarged portion 42 thereon. Preferably, the enlarged portion 42 of each bearing 41 has a removable thin-walled spacer sleeve 43 snugly or slidably mounted thereon which may normally bear against the upper surface of the enlarged portion 40 of the corresponding bottom roll bearing 36 therebeneath, thus limiting the extent of intermeshing relationship of the flutes of the corresponding set of top and bottom drafting rolls. The reason why a sleeve 43 is preferred on the enlarged portion 42 of each bearing 41 is to facilitate ease in varying the intermeshing relationship of a corresponding set of rolls simply by removing spacer sleeve 43 from the enlarged portion 42 of the top roll bearing 41 at each end of a corresponding top roll and replacing the same with another sleeve of the same internal diameter but of a slightly different external diameter. If desired, sleeve 43 on the enlarged portion 42. of each top roll bearing 41 may be omitted, but in this instance, it then would be necessary to replace a bearing 41 whenever an enlarged portion 42 of different diameter was to be used.

The bottom delivery rolls 34' of all the primary drafting units are axially coextensive by being rigidly interconnected so that a single motive means imparts rotation to all the delivery rolls of the primary units in fixed relationship and so all the primary webs Wl-W4 are delivered from the primary drafting units in proper relationship to each other during normal operation of the drafting units as well as during any periods of acceleration and deceleration of the same. As shown in FIGURES 2A and 2B, the bottom delivery rolls of adjacent primary units may be rigidly interconnected by corresponding connector shafts 50 therebetween and suitably secured thereto, as by means of a positive clutch 51 and a sleeve 52. The distal ends of the bottom delivery rolls of primary drafting units I and IV have respective extension shafts 54, 55 fixed thereto suitably journaled on the frames of the corresponding units I, IV.

Extension shaft 55 is coupled to the output shaft of a suitable gear transmission device 56 (FIGURE 2B) carried by the frame of drafting unit IV and whose input shaft is operatively connected to a stub shaft 57, as by sprocket wheels 60, 61 and an endless sprocket chain 62. Stub shaft 57 may be driven from the bottom back or feed roll 31 of secondary drafting unit V through a gear train 63. Intervening gears, which may be identical for each drafting unit and will be later described, connect the bottom delivery roll of secondary drafting unit V to the other bottom drafting rolls thereof, and a motive means 65, such as an electric motor, drives the bottom delivery roll of secondary unit V, thus providing a common drive means for all the drafting units I-V.

As heretofore stated, after composite web W5 is drafted, it may be formed into sliver S and coiled into can 25. Therefore, the drafted web from secondary drafting unit V is shown being drawn through a condenser 67 and a trumpet 70 by a pair of calender rolls 71, preferably of the fluted intermeshing type shown in my US. Patent No. Re. 25,520 dated Feb. 11, 1964. Rolls 71 feed sliver S through a suitable coiler mechanism 72 into can 25. One of the calender rolls 71 may be journaled on a shaft 73 and the other calendar roll 71 may be fixed on a shaft 74. Shafts 73, 74 are carried by the frame of drafting unit V and shaft 74 may be drive from the bottom delivery roll 34' of drafting unit V by a gear train 76. The shaft of motor 65 may be connected to the delivery roll of secondary drafting unit V by a suitably controlled clutch 77 (FIGURE 2B), as is Well known.

It is thus seen that all the drafting units I-V are driven by motor 65 and that the speed of the delivery rolls 34, 34' of all the primary drafting units I-IV is of a fixed ratio to the speed of the feed rolls 31, 31 of secondary drafting unit V. Means are also provided for varying the draft imparted to the textile material by each of the drafting units independently of the others without necessarily changing the speed of the delivery rolls, thus permitting the drafting of a type of fibers through any one of the primary drafting units I-IV different from the type being drafted through any one or more of the other primary drafting units. Also, as exemplified in FIGURE 6, the sets of drafting rolls 31, 31'; 32, 32'; 33, 33'; and 34, 34 of each drafting unit I-V are relatively adjustable on corresponding roll stands 80 independently of the drafting rolls of the other drafting units so that each primary drafting unit may draft fibers of different average staple length than the fibers being drafted by another or all the other primary drafting units. Accordingly, as shown in FIGURE 6, each roll stand -80 may have a longitudinal slot 81 in its upper bridging portion through which a screw 82 for each bearing block 37 extends for securing the bearing blocks in the desired adjusted position.

The means for varying the amount of draft and imparting rotation to the intermediate and back drafting rolls of each drafting unit comprises a pair of gear trains (FIGURES 7 and 8) adjacent opposite sides of each drafting unit and which transmit rotation from each bottom delivery roll 34' to the remaining bottom rolls of the respective unit. The top drafting rolls are driven by engagement with the bottom drafting rolls or stock passing therebetween, as is usual. In FIGURES 7 and 8, which represent any one of the drafting units I-V, it will be observed that the bottom delivery roll 34' there shown has a small gear 83 (FIGURE 7) fixed thereon meshing with a larger crown gear or change gear 84 mounted on a stub shaft 85 in fixed axial relation with a gear 86 meshing with a gear 87 fixed on rear intermediate bottom drafting roll 32'. Stub shaft 85 may be in the form of a shoulder bolt adjustable in a slotted bracket 90 (FIG- URE 2B) to accommodate change gears 84 of different sizes for changing the relative speeds of rolls 32', 34' and thereby to change the amount of draft effected by the corresponding drafting unit without changing the speed of delivery rolls 34, 34'.

The end of each rear intermediate drafting roll 32' remote from gear 87 has a gear 91 fixed thereon (FIG- URE 8) meshing with a pair of gears 92, 93 which may be mounted in the same manner as change gear 84 and have respective gears 94, 95 in fixed axial relation therewith' Gears 94, 95 mesh with respective gears 96, 97 fixed on front intermediate drafting roll 33' and feed roll 31, respectively. Gears 9294 also may be replaced by gears of different sizes to effect changes in draft as may be required when changing from one type of stock to another.

Any suitable means may be employed for applying yieldable downward pressure to each end of each top drafting roll 31-34, such as is shown in US. Patents Nos. 2,412,357 and 3,143,772, for example. Such pressure applying means may include a separate springloaded plunger 98 (FIGURES 4 and 5) bearing against each bearing 41 or its sleeve 43. The spring-loaded plungers at each side of each drafting unit may be carried by supports 99' overlying the corresponding bearings 41.

As stated earlier, primary webs W1-W4 are drawn along table 21 by calendering devices 24. As shown in FIGURES 2A and 2B, table 21 is in the form of a row of plates 100 whose proximal ends are separated as in FIGURE 10 to accommodate calendering devices 24. Plates 100 are suitably secured to corresponding bearing blocks 106 mounted on brackets 101. Each bracket 101 may take the form of a cantilever (FIGURE 9) suitably secured to the frame of the corresponding primary drafting unit. As shown in FIGURES 9 and 10, each calendering device 24 may comprise a pair of top and bottom intermeshing fluted calender rolls 102, 103 whose reduced opposite ends are rotatably mounted in respective top and bottom bearings 104, 105 mounted in substantially U-shaped bearing blocks 106. The diameters of bearings 105 and a sleeve 107 on each bearing 104 maybe about equal to the pitch diameter of the fluted portions of respective calender rolls 103, 102. Sleeves 107 are provided for a purpose similar to that of the sleeves 43 on top roll bearings 41 (FIGURES 4 and i.e., to permit changing the depth of mesh of each top calender roll 102 with the respective roll 103 in accordance with the desired speed of the webs while maintaining desired tension draft therein.

Calender rolls 102, 103 preferably are of greater diameter than drafting rolls 31-34, 31'-34- and, thus, the weight of each top calender roll 102 may serve to cause each top calender roll to engage the corresponding textile web or webs with the desired pressure. If desired, however, pressure applying means of the type heretofore described for the top drafting rolls may be used for the top calender rolls 102. In FIGURES 9 and 10, for example, a spring-loaded plunger 110 is shown bearing against each bearing sleeve 107. The stem of each plunger 110 is loosely mounted in a sleeve 111 carried by a bar 112 fixed to and extending between bearing blocks 106. A compression spring 113 engages the flanged upper portion of sleeve 111. Spring 113 also engages a washer 114 adjustably supported on the stern of plunger 110 by a nut 115, whereby the force of spring 113 acting on plunger 110 may be adjusted. A suitable clearer device or board 116 (FIGURE 9) may be supported by each bar 112 to engage and prevent excessive accumulation of fibers on each top calender roll 192.

In this embodiment of the invention, the drafting rolls of all the drafting units I-V are conveniently on about the same level. Therefore, the front of foremost plate 100' of table 21 is inclined upwardly and forwardly (FIGURE 1) to guide the composite web W5 to the drafting rolls of secondary drafting unit V. A carrier device 120 may be provided adjacent the upper edge of the foremost plate 100 of table 21 to assist in advancing composite web W5 to drafting unit V. Carrier device 120 comprises a pair of intermeshing fluted rolls 121 which may be mounted on the frame of secondary drafting unit V in the same manner as that in which calender rolls 102, 103 are mounted on bracket 101 in FIGURES 9 and 10. Therefore, a detailed description and illustration of carrier device 120 is deemed unnecessary.

The bottom calender rolls of all the calendering devices 24 and carrier device 120 are preferably of the same diameter and may be driven at the same speed and at a speed in fixed ratio to the speed of the primary drafting units from a jack shaft 125 extending between table 21 and the front portions of the frames or housings of the primary drafting units. Suitable take-off gearing 126 connects bottom roll extension shaft 54 (FIGURE 2A) to jack shaft 125 for driving the same in proper timed relation to the bottom delivery rolls 34' of primary units I-IV. Shaft 125 is journaled in power transmission or gear units 130, one of which is mounted on each bracket 101 (FIGURE 9). With the exception of the foremost transmission unit 130 in FIGURE 2B, the output shafts of the remaining transmission units 130 may be connected to corresponding bottom calender rolls 103 by a positive clutch means 131. Each power transmission unit 130 may be of a type shown in FIGURE 7 of US. Patent No. 2,975,489, to which reference is made for a detailed description thereof. It will be observed in FIGURE 2B that a sprocket wheel 133 may serve the same purpose as one of the clutch means 131 to drive the bottom roll of carrier device by means of a sprocket chain 134 and another sprocket wheel 135.

Suitable spool-shaped selvage guides (FIGURES 2A, 2B and 3) may be adjustably mounted on table 21 and on the rear portion of the frame of secondary drafting unit V for guiding and smoothing the selvages of the webs as shown in FIGURES 2A and 2B during advancement of the same from the primary to the secondary drafting units. The selvage guides 140 may be mounted as shown in FIGURE 3, wherein a pair of the selvage guides are shown engaging opposite selvages of primary web W'l. Each selvage guide 140 may have a reduced stem 141 penetrating a transverse slot 142 in table 21 and on which a washer 143 and nut 144 are mounted for securing each selvage guide in adjusted position.

In setting up the apparatus for operation, it is desirable that the feed rolls 31, 31 of the primary drafting units have an evening elfect on the fibrous material being directed into the same, particularly when such fibrous material is in the form of groups of individual slivers S being drawn from individual cans C as shown in FIG- URE 1. To this end, the diameters of the sleeves 43 (FIGURE 5) and the enlarged portions 40 of the bearings 36 should be such relative to the diameters of the feed rolls 31, 31 of the primary drafting units I-IV that the top feed rolls thereof will be supported by the slivers S instead of by engagement of the spacer sleeves 43 with the enlarged portions 40 of the corresponding bearings 36. By such an arrangement, the feed rolls 31, 31' of the primary drafting units I-IV will advance the slivers S into the drafting zones between each set of feed rolls 31, 31' and the next succeeding set of drafting rolls 32, 32' at relatively faster speed when a relatively thin place in the slivers S being directed to the corresponding primary drafting unit is passing between the corresponding feed rolls 31, 31'. Conversely, when a relatively thick place or a place of higher density in the corresponding slivers is passing between the feed rolls 31, 31', the speed of the slivers S entering the corresponding drafting zone will be decreased, thus contributing to uniformity in the density or weight per unit length of the webs Wl-W4 being formed. The diameters of the sleeves 43 and the enlarged portions 40 of the bearings 36 relative to the diameters of the fluted portions of the remaining drafting rolls 32-34, 32'-34' of all the primary drafting units I-IV and of all the drafting rolls of the secondary drafting unit V should be such that the fibrous material being drafted thereby will not normally raise the corresponding top drafting rolls; i.e., the corresponding spacer sleeves -43 (FIGURE 5) normally will rest upon the enlarged portions 40 of the corresponding bottom roll bearings 36 at all times. Sleeves 43, on feed rolls 31, 31 of the primary units I1V prevent the bottoming of corresponding top tolls 31 against the bottom rolls 31':

It is important that the weight per unit length of each primary web W1W4 is maintained constant and in accurate proportions to the weight of the other primary webs then being drafted through the primary drafting units I-IV so that the proportions of various types of fibers present in the composite web W5 meet the required specifications which may appear on labels applied to various products made from the fibers thus blended. On the other hand, it is also important that the delivery or linear speed of all the primary webs Wl-W4 issuing from the primary drafting units I-IV is substantially the, same with consideration being given to the aforementioned tendencies for different types of fibers to slip different amounts relative to the drafting rolls, as well as the necessity for maintaining the primary webs W1W4 under proper tension draft. Further, the tension draft applied to the various webs as they advance along table 21 may vary slightly between successive calendering devices 24 and between the foremost calendering device 24 and the carrier device 120 (FIGURE 2B).

It is apparent, therefore, that the diameter of the sleeves 43 on the top roll bearings 41 of the various top delivery rolls 34 may vary at each primary drafting unit relative to the other primary drafting units. Of course, if the delivery speed of any one of the primary webs W1- W4 becomes relatively high or low in order to accommodate all the conditions mentioned heretofore, it is apparent that any changes thus effected in the amount of draft to be imparted to the corresponding fibrou material by the corresponding drafting unit would also change accordingly and may be compensated for by making appropriate changes in the size of the corresponding gear 84 (FIGURE 7) and/or in the gears 92-95 (FIGURE 8) of the corresponding primary drafting unit. The desired speed of the feed rolls 31, 31' of the secondary drafting unit may be attained by making appropriate changes in the size of one or more of the gears in the gear train 63 (FIGURE 2B).

Generally, any drafted fiber web is thicker longitudinally of its central portion than it is at its outer edges. This results in the web gradually increasing in width when it is being pulled between web advancing rolls, such as rolls 102, 103 (FIGURE 9). I have discovered that, owing to the fact that synthetic fibers have slicker or smoother and more slippery surfaces than natural fibers, such as cotton fibers, synthetic fiber webs spread laterally when being pulled, to a greater extent than cotton webs. Therefore, when blending synthetic and cotton fibers according to the method of the instant invention, the slivers S are so arranged upon entering the respective primary drafting units IIV that any synthetic fiber web or webs emerging therefrom are compensatively narrower than any cotton web or webs emerging therefrom so that, by the time that the composite web W formed therefrom reaches the secondary drafting unit V, the pulling force applied uniformly throughout the width of the Webs will have caused the synthetic fiber web or webs to increase in width to a greater extent than the natural fiber web or webs so that all the webs of the composite web W5 will be of substantially the same width, thus further contributing to uniformity of the blend.

In accordance with the method of this invention, it can be appreciated that each primary drafting unit (1) is capable of drafting textile fibers of a different type and/ or average staple length than that of the fibers being drafted by the other primary drafting units, (2) is capable of applying a. different amount of draft to corresponding fibers than that applied by the other primary drafting units, and (3) may deliver the corresponding primary web therefrom at substantially the same speed as that at which the primary webs are delivered from the other primary drafting units and in accordance with the speed at which the webs are to be drawn into the secondary unit V.

Even though the bottom delivery rolls 34' of all the primary drafting units IIV may be of the same diameter and rotate at the same speed, and the fibers being drafted by any one of the primary units may slip relative to corresponding drafting rolls to a greater or lesser degree than the fibers being drafted by another or others of the primary units, it should be noted that the delivery speed of all the primary webs may be substantially the same and that minor adjustments may be made in the delivery speeds of the primary webs issuing from the primary drafting units, without changing the speed of the delivery rolls 34' thereof, thus insuring that each primary web may be subjected to the required amount of tension draft in its course to the table 21. Further, it should be noted that the primary webs are stacked successively in superposed relationship so that at least one of the primary webs is sandwiched between two other pri- '10 mary webs, and that the amount of tension draft applied to the primary webs may be varied in their course along table 21 and to secondary drafting unit V by making appropriate adjustments in the intermeshing relationship of the fluted calender rolls of calendering devices 24 and carrier device in the manner heretofore described.

It is apparent that the greater the number of layers of fibers, as successive primary webs are deposited upon a preceding web or webs, the lesser may be the amount of tension draft required therein, although the total amount of tension draft may be accumulative as the number of layers of fibers increases. For example, a tension draft of 1.04 may be required in the first primary web W1, an accumulated tension draft of 1.05 may be required in the two superposed primary webs W1, W2, an accumulated tension draft of 1.06 may be required in the three superposed webs W1, W2, W3, and an accumulated tension draft of 1.07 may be required in the completed composite web W5.

Another important feature of the instant invention is that the composite web W5 formed by superposing the plurality of primary webs W1-W4 passes directly from the primary units into the secondary drafting unit V which drafts and reduces the composite web to the final desired weight per unit length, either in the form of a Web which may be rolled up or which is condensed into a final sliver and coiled into a can for further processing. The superposing of primary webs, wherein one or more of the webs may be formed of a different type or length fibers than the other webs, effects a uniform distribution of the fibers of each web throughout the width of the composite web and the drafting of the composite web through the secondary drafting unit blends and intersperses the various types of fibers with each other in a homogeneous manner to produce a more thorough blending of the various fibers and a more uniform weight per unit length of the fibrous material issuing from the secondary drafting unit than has heretofore been attainable to my knowledge.

As an example of the complicated types of blends of fibers which may be obtained by practicing the method of the present invention, it may be assumed that a secondary sliver S weighing sixty grains per yarn is to be obtained having twenty percent cotton fibers of about one inch average staple length, thirty percent Dacron fibers of about two inches average staple length, twenty-five percent Orlon fibers of about one and nine-sixteenths inches average staple length and twenty-five percent Acrilan fibers having three inches average staple length therein. It may be assumed further that the sliver S to be obtained is to be made from card slivers, each of which weighs six ty grains per yard. Although there are various ways in which the various types of card slivers may be arranged in the primary drafting units IIV to obtain the desired blended sliver therefrom, one example as to how the card slivers may be arranged will now be given.

In setting up the apparatus, ten ends or card slivers of cotton having one inch average staple length may be directed from separate cans C into primary drafting unit I; sixteen ends of Dacron fibers having an average staple length of two inches may be directed from separate cans into primary drafting unit II; ten ends of Orlon fibers having one and nine-sixteeths inches average staple length may be directed into primary drafting unit III; and ten end of Acrilan fibers having three inches average staple length may be directed into primary drafting unit IV. The total draft imparted ot the fibers at the primary drafting units IIV would be 5, 5.3, 4 and 4, respectively. Thus, the primary webs W1-W4 issuing from the drafting units IIV would weigh 120; 180, and 150 grains per yard, respectively, and the composite web W5 formed therefrom thus would weigh 600 grains per yard. The 600 grains per yard composite web W5 would then be subjected to a draft of 10 as it is passed through secondary drafting unit V and condensed through condenser 67 and trumpet 1 1 70 to form the blended sliver S weighing 60 grains per yard.

It can thus be appreciated that the delivery speed of and amount of draft imparted to the fibers by the secondary drafting unit V are substantially greater than that of each primary drafting unit.

Heretofore, the only method I am aware of by which different types of card slivers could be :blended in accurate proportions to obtain a complicated blend such as that described has been to produce card slivers of different weights per unit length and then draft several such different types of slivers through a common drafting unit. Even then, many proportions of different types of fibers could not be obtained. Obviously, variation in the size of card slivers has undesirably reduced the production capabilities of one or more carding machines in the mill. In producing a 60 grain-per-yard blended sliver of the type mentioned in the foregoing example, but practicing the prior art method, as many as four or more different sizes of card slivers varying from about 44 to 60 grains per yard may be required. Also, the various types of fibers would not be distributed, intermixed or drafted with the uniformity or efficiency obtainable according to the instant method.

It is important to note that the primary webs W1-W4 are crimped by the fluted drafting rolls of the primary drafting units to lend tensile strength thereto to assist in preventing rupture of the thin primary webs as they pass in engagement with the curled guide plates 20. This is particularly important with high speed operation of the delivery rolls 34, 34 of the primary drafting units I-IV. A further crimping of the webs occurs at each of the calendering devices 24 and the carrier device 120 which not only lends tensile strength to the various webs as they are being advanced along table 21 to secondary drafting unit V, but also intermixes the fibers of adjacent superposed webs in the formation of the composite web W5, thus further assisting in the homogenous distribution of the various types and lengths of fibers throughout the blend.

Although the fibrous material or stock is sh wn in the accompanying drawings being directed to the primary drafting unis I-IV in the form of slivers being drawn from individual cans, it is contemplated that the incoming stock may be taken from sliver lap rolls or ribbon lap rolls. However, since it is necessary that all the fibers are withdrawn from any one sliver lap roll or ribbon lap roll at a given speed, the spacer sleeves 43 (FIGURE for the fed rolls 31, 31 of any primary drafting units receiving stock from a sliver lap roll or ribbon lap roll would have to be of such diameter that they would also remain in engagement with the enlarged portions 40 of the corresponding bottom feed roll bearing 36 at all times during operation of a corresponding primary drafting unit or units, since a variation in the rate of feed of various portions of the webs coming from the ribbon lap rolls or sliver lap rolls to a particular drawing frame could not be tolerated.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim:

1. A method. of blending textile fibers which comprises directing separate masses of fibrous material into and through respective ones of a plurality of primary drafting units, while delivering the thus drafted fibrous material from each primary drafting unit in the form of a broad, thin fibrous web, while successively arranging the webs emerging from the drafting units in superposed relationship, while directing the superposed webs into and drafting them through a common secondary drafting unit, and while applying a progressively increasing tension draft to the webs from the primary drafting units in their course to the common secondary drafting unit so as to aid in unitary longitudinal movement of the superposed webs to the common secondary drafting unit.

2. A method according to claim 1 which includes applying lateral crimp to the webs as they are successively arranged in superposed relationship.

3. A method according to claim 1 wherein at least one of the webs being delivered by the primary drafting units is formed of relatively short staple fibers and at least one other web being delivered by the primary drafting units is formed of relatively long staple fibers and wherein the webs are arranged in superposed relation with the web of the shortest staple fibers being the lowermost and with the web of the longest staple fibers being the uppermost and wherein the webs are directed in this superposed relationship into and through the common secondary drafting unit.

4. A method according to claim 1 wherein the webs being delivered from the primary drafting units include a first web formed of relatively short staple fibers, a second web formed of relatively long staple fibers, and at least one-third web formed of intermediate length fibers, and wherein the webs are arranged in superposed relationship with the web of the shortest fibers being lowermost, the web of the longest fibers being uppermost, and with the web of intermediate length fibers being positioned therebetween, and are directed, while in this superposed relationship, into and through the common secondary drafting unit.

5. A method according to claim 1, wherein each primary drafting unit includes a pair of intermeshing fluted delivery rolls, and wherein the fibrous material being directed into one of the primary drafting units has different drafting characteristics than the fibrous material being directed into another one of said primary drafting units, and wherein the fibrous webs are delivered from each primary drafting unit at substantially the same linear speed by varying the extent of intermeshing relationship of the delivery rolls of the primary units relative to each other, to cause the corresponding webs to emerge therefrom at substantially the same speed.

6. A method according to claim 1 wherein the fibrous material being directed into and through at least one of the primary drafting units is passed through a drafting zone therein of different effective length than the drafting zone of one other of the primary drafting units and is of different staple length from the fibrous material passing through the other primary drafting unit.

7. A method according to claim 1, which includes the step of applying a lateral crimp to the superposed webs in their course from the primary drafting units to the secondary drafting unit to enhance the cohesiveness and tensile strength of the webs by directing the superposed webs through intermeshing fluted calender rolls.

8. A method according to claim 1, which comprises the step of applying a squeezing compacting pressure to the superposed webs in their course from the primary drafting units to the common secondary drafting unit by directing the superposed webs through a confined passage to blendingly intermingle fibers of adjacent webs.

9. A method of blending fibers which comprises directing separate masses of fibrous material into and through respective ones of a plurality of drafting units while forming a plurality of attentuated thin fibrous webs therefrom in which at least one web is formed of relatively short staple fibers and at least one other web is formed of relatively long staple fibers, while arranging the webs in superposed relationship with the web of the shortest staple fibers being the lowermost and with the Web of the longest staple fibers being the uppermost of the superposed webs, and while directing the webs, in this superposed relationship, into and through a drafting zone.

10. A method according to claim 9 which includes applying lateral crimp to the webs as they are arranged in superposed relationship.

11. A method according to claim 9, wherein the lowermost web is formed of cellulosic fibers.

12. A method according to claim 9, wherein the lowermost web is formed of cotton fibers and wherein the uppermost web is formed of synthetic fibers.

13. A method of blending fibers which comprises directing separate masses of fibrous material into and through respective ones of a plurality of drafting units while forming a plurality of attenuated thin fibrous webs therefrom in which a first web is formed of relatively short stable fibers, a second web is formed of relatively long staple fibers and at least one third web is formed of intermediate length fibers, while arranging the webs in superposed relationship With the web of the shortest fibers being the lowermost, the web of the longest fibers being the uppermost of the superposed webs, and with the web of intermediate length fibers being positioned therebetween, and while directing the webs, while in this superposed relationship, into and through a drafting zone.

14. A method of blending different types of textile fibers which comprises directing fibrous material of a first type into and through at least one first primary drafting unit, while directing fibrous material of a second type having different drafting characteristics than the first type into at least one second primary drafting unit while imparting a different draft thereto than that being imparted to the first type of fibrous material, while directing fibrous material of a second type having difmary drafting unit, delivering the thus drafted fibrous material from each primary drafting unit at substantially the same linear speed in the form of a broad, thin fibrous web, while arranging the webs thus emerging from the drafting units in superposed relationship by successively positioning the webs from said second and third primary drafting units in superposed relation to the web from said first primary drafting unit at respective spaced points along the path of movement of the latter web,

directing the superposed webs into and drafting them through a common secondary drafting unit, and while,

applying a progressively increasing tension draft to the webs from the primary drafting units in accordance with the superpositioning of successive webs in their course to the common secondary drafting unit so as to aid in unitary longitudinal movement of the superposed webs to the common secondary drafting unit.

15. A method of blending different types of textile fibers which comprises directing synthetic fibers into and drafting them through at least one first primary drafting unit, while directing natural fibers into and drafting them through at least one second primary drafting unit, delivering the thus drafted fibers from each primary drafting unit in the form of a broad, thin fibrous web,

controlling the width of the webs being formed by the primary drafting units such that the synthetic fiber web emerging from the first primary drafting unit is of a predetermined width less than the width of the natural fiber web emerging from the second primary drafting unit, while arranging the webs thus emerging from the drafting units in superposed relationship with opposed longitudinal edges of the natural fiber web extending substantially equidistantly outwardly of opposed longitudinal edges of said synthetic fiber web, and while directing the superposed webs into and drafting them through a common secondary drafting unit and while applying a pulling force to the superposed webs while compressing the same in their course to the secondary drafting unit such as to increase the width of the superposed webs while increasing the width of said synthetic fiber web to a greater extent than the natural fiber web so the synthetic and natural fiber webs are of substantially the same Width upon reaching said secondary drafting unit. 16. A method of blending different types of textile fibers which comprises directing synthetic fibers into and through at least one first primary drafting unit, while directing natural fibers into at least one second primary drafting unit and imparting a different draft thereto than that being imparted to the synthetic fibers,

delivering the thus drafted fibers from each primary drafting unit at substantially the same linear speed in the form of a broad, thin fibrous Web,

controlling the width of the webs being formed by the primary drafting units such that the synthetic fiber web emerging from the first primary drafting unit is of a predetermined width less than the width of the natural fiber web emerging from the second primary drafting unit, while arranging the webs thus emerging from the drafting units in superposed relationship with opposed longitudinal edges of the natural fiber web extending substantially equidistantly outwardly of opposed longitudinal edges of said synthetic fiber web, and while directing the superposed webs into and drafting them through a common secondary drafting unit and applying a compressive pulling force uniformly throughout the width of the superposed webs in their course to the secondary drafting unit such as to increase the width of the superposed webs while increasing the width of said synthetic fiber web to a greater extent than the natural fiber web so the synthetic and natural fiber webs are of substantially the same witdh upon reaching the said secondary drafting unit.

References Cited UNITED STATES PATENTS 1,722,066 7/1929 Nigrin et al. 19243 2,132,524 10/1938 Booth 19145.5 3,432,890 3/1969 Burnham et a]. 19-243 XR 630,813 8/1899 Meats 19243 2,661,503 12/1953 Longstreet 19157 XR 2,896,269 7/1959 Gardella et a1 l9243 3,063,101 11/1962 Andreani 19243 3,067,471 12/1962 Noda 19243 3,143,772 8/1964 Whitehurst 19272 3,203,051 8/1965 Whitehurst 19239 3,327,356 6/1967 Andreani 19-243 3,128,506 4/1964 Brandt 19 -243 XR 3,216,064 11/1965 Kates 19-145.5 XR

FOREIGN PATENTS 463,447 3/ 1937 Great Britain. 38/5369 5/1963 Japan. 40/12,256 6/1965 Japan.

ROBERT R. MACKEY, Primary Examiner US. Cl. X.R.

Patent 304 Dated February 17, 1970 Inventor(s) J. R. Whitehurst It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, Line 28, "is". should be --in--; Column 4, Line 48,

"he" should be -the--; Column 6, Line 2, "drive" should be -driven--; Column 10, Line 43, "yarn" should be -yard-;

same column, Line 63, "nine-sixteeths" should be --ninesixteenths--;

same column, Line 65, "end" should he --ends--; same column,

Line 67, "ot" should be -to--; Column 11, Line 43, "unis" should be --units--; same column, Line 49, "fed rolls should be -feed rolls-w 4 v I in I I rmn ijm i Column 13, Line33, after "material" insert --into and through a third primary drafting unit--, same column, same line, delete "while", same column, Line 34, delete, "directing fibrous material of a second type having dif", same column, Line 35, delete "mary drafting unit, Column 14, Line 42, "w'itdh' should be --width- IN THE LIST OF REFERENCES Nigrin et al Patent No. "l, 722, 066" should be Patent No. --1, 722, 006-- SIGNED A'ND SEALED 3 AM JUL 2 8 1970 Edward M. Fletcher, In

WILLIAM E- 6080mm, JR. W 0mm Gomissionar of Patent;

FORM PO-IOSO (IO-691 

